Wheelchair Power Head Linkage Lift for Large Swing Angle Locking
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Solution Overview
Problem
Existing wheelchair electric head clamping mechanisms are large in size and limited in swing angle, necessitating a more compact and efficient design with increased swing capability.
Innovation Solution
An electric lifting mechanism comprising an electric push rod, first and second connecting rods, a swing arm, and a safety device with locking nuts and bolts, allowing for a reduced size and enhanced swing angle through a novel hinge configuration and locking mechanism.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a bolt connecting clamping block is used to fix the electric wheelchair head and wheelchair, then the clamping mechanism is simple in structure, but the size is large and the swing angle is limited
Solution Approach 1:
The clamping mechanism is divided into modular components: a clamping block for fixation, an electric push rod for actuation, and a four-bar linkage mechanism (comprising first connecting rod, second connecting rod, and swing arm) for motion transformation. This segmentation allows each component to be optimized independently, achieving compact size and increased swing angle while maintaining structural simplicity
Solution Approach 2:
The mechanism transitions from a static bolt connection to a dynamic four-bar linkage system. The swing arm can rotate through a larger angle while the electric push rod provides controlled actuation. The dynamic configuration allows the mechanism to achieve greater swing angle (increased from conventional limited angles to over 90 degrees) within a compact footprint by utilizing rotational degrees of freedom
2Length of moving object
If an electric push rod is used as the driving part to increase the swing angle, then the swing capability is improved, but the size of the mechanism becomes large
Solution Approach 1:
The mechanism uses a four-bar linkage configuration that transforms the linear motion of the electric push rod into rotational motion of the swing arm through a spatial arrangement of connecting rods. This dimensional transformation allows compact packaging of the mechanism while achieving large swing angles, as the motion is distributed across multiple links rather than requiring a single large actuator
Solution Approach 2:
The first connecting rod and second connecting rod are arranged in a nested configuration where the motion of one link is coupled with the motion of another. This nesting allows the mechanism to achieve complex motion patterns (large swing angle) within a compact volume by having the links occupy overlapping spatial regions during operation
3Length of moving object
If the hinge point of the swing arm is positioned conventionally, then the mechanism is simple, but the swing angle is limited
Solution Approach 1:
The hinge points are positioned asymmetrically: the first hinge connects the swing arm to the first connecting rod at one location, while the second hinge connects the swing arm to the second connecting rod at a different location. This asymmetric hinge configuration creates an optimized four-bar linkage geometry that enables larger swing angles while maintaining a compact mechanism layout, breaking the symmetry of conventional equal-armed linkages
Data Source
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AI summary
The invention discloses an electric lifting mechanism for a wheelchair electric vehicle head with a safety device comprising a connecting block (1), an electric push rod (2), a first connecting rod (3), a second connecting rod (4) and a swing arm (5). The upper end of the electric push rod (2) is hinged on the upper end of the connecting block (1), the pushing end part of the electric push rod (2) is respectively hinged with the upper end of the first connecting rod (3) and the second connecting rod (4), and the lower end of the first connecting rod (3) is hinged with the middle part of the connecting block (1). The lower end of the second connecting rod (4) is hinged with the upper part of the swing arm (5), the upper end of the swing arm (5) is hinged in the middle of the connecting block (1), and the hinge point of the swing arm (5) and the connecting block (1) is located above the hinge point of the upper part of the swing arm (5) and the lower end of the second connecting rod (4). The first connecting rod (3), the second connecting rod (4) and the swing arm (5) constitute a group of connecting rod mechanisms, which can greatly increase the swing angle of the swing arm (5), and has the advantages of small size and small mechanism. In addition, the invention is provided with at least one locking nut (6), which can abut against the swing arm (5) to lock the swing arm.